Concurrent Force System - Definition, Types

What is Concurrent Force System?

The word "concurrent force system" has two main parts: "concurrent" and "force system". Here, concurrent implies that "the things criss-cross throughout a single point," whereas "force system" implies a "group of forces." The definition of a concurrent force system can be easily determined by merging the definitions of these two.

Concurrent Force System Definition

A concurrent force system can be defined as, " When forces are applied to an object in such a way that their lines of action pass through a single point, they are referred to as concurrent forces."

Types of Concurrent Force Systems

When a system of force on an object creates a concurrent system of force, then there are two possibilities for the line of action of the forces in the force system. All of the forces' lines of action may be in the same plane or may not be in the same plane. For the reasons stated above, the concurrent force system can be of two types:

1. Concurrent coplanar force system
2. Concurrent non-coplanar force system

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Concurrent Coplanar Force System

A group of forces in which the line of action of all the forces lies in the same plane and these pass through a common point is called a concurrent coplanar force system. A force system on the pin of a joint in a planar truss is an example of a concurrent coplanar force system.

Concurrent Non-coplanar Force System

A concurrent non-coplanar force system is a group of forces whose lines of action do not all lie in the same plane but pass through a common point. A force system on the pin of a joint in a space truss (example: transmission tower) is an example of a concurrent non-coplanar force system.

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Concurrent Force System in Equilibrium

An object is in static equilibrium if the net force and the net moment about any point on the object due to forces are equal to zero. As we know, in a concurrent force system, all the forces' line of action passes through a common point. So if we consider the net moment at the point of concurrency, then the net moment will be zero.

In short, we can conclude that the net moment in a concurrent force system is always zero. To check the equilibrium condition of any object acted upon by a concurrent force system, we need to check for force equilibrium only. Equilibrium conditions for both types of concurrent systems are mentioned below.